99 International Dt466e overheating

[Compass]

Hey all, I'm hoping for some direction.

My 99 11 window front engine Amtran with AT 545 has about 300 miles on an engine rebuild from a knowledgeable and reputable mechanic. At the time, he replaced the radiator and thermostat as well. Also, the brakes were serviced.

My problem...I can't climb a long hill (over 1 mile) without the engine overheating and alarming. ELC coolant level is good.

I hate to bring it back again but realize I may have to, but any ideas as to why overheat? I'm barely crawling!

Thanks 😊

[ewo1]

Originally Posted by Compass

Hey all, I'm hoping for some direction.

My 99 11 window front engine Amtran with AT 545 has about 300 miles on an engine rebuild from a knowledgeable and reputable mechanic. At the time, he replaced the radiator and thermostat as well. Also, the brakes were serviced.

My problem...I can't climb a long hill (over 1 mile) without the engine overheating and alarming. ELC coolant level is good.

I hate to bring it back again but realize I may have to, but any ideas as to why overheat? I'm barely crawling!

Thanks ��

First thing I would look at is the radiator itself, are the fins clogged/dirty? Is air getting thru?

You can get some quality cleaner at an A/c supply house, a place that serves a/c techs, not the retail public. They have great cleaners for cleaning the a/c condenser coils.

https://www.youtube.com/watch?v=PGC2gOkOSTk

They also sell fins combs, for straightening out the fins when the get smashed closed.

https://www.youtube.com/watch?v=mwzwboqN5Cw

Then I would look at, what type of fan you have. Is it working properly?

that is where I would start, easy and cheap to do.

[rossvtaylor]

If you've got a fresh rebuild engine and a new radiator, I would definitely be looking at your fan and fan clutch. When it gets hot, can you pull over and pop the hood and make sure the fan is turning aggressively? It will turn some, even if the fan clutch isn't locked, just because of the friction. But it should sound like a turbine and moving a ton of air when it's hot. If your fan clutch is not locking the fan, then that would definitely be a problem when climbing hills.

[rffffffff]

Originally Posted by rossvtaylor

If you've got a fresh rebuild engine and a new radiator, I would definitely be looking at your fan and fan clutch. When it gets hot, can you pull over and pop the hood and make sure the fan is turning aggressively? It will turn some, even if the fan clutch isn't locked, just because of the friction. But it should sound like a turbine and moving a ton of air when it's hot. If your fan clutch is not locking the fan, then that would definitely be a problem when climbing hills.

I had this same experience and it was my fan clutch. When going up a hill at some point the engine sound should change very significantly, especially if it’s a flat nose front engine, and you’ll absolutely know when the fan kicks on. Not sure about a dognose but if it’s an FE and you’re not hearing the fan when it’s hot it’s very likely the clutch. Fwiw my bus also will engage the fan when I first start it for a moment, and it’s kind of a comfort feeling for me when I hear it but I don’t know if they all do.

[cadillackid]

its normal for the fan to run full bore for a minute or 2 when first starting out.. my DEV bus does it and even on a dognose bus i hear that fan spinning even over the sound of the DT engine..

[BamaBus]

Originally Posted by Compass

My 99 11 window front engine Amtran with AT 545 has about 300 miles on an engine rebuild from a knowledgeable and reputable mechanic. At the time, he replaced the radiator and thermostat as well. Also, the brakes were serviced.

My problem...I can't climb a long hill (over 1 mile) without the engine overheating and alarming. ELC coolant level is good.

I hate to bring it back again but realize I may have to, but any ideas as to why overheat?

I suspect the fan clutch as well. You can get an idea by turning the fan by hand (engine off of course) and you should feel resistance. If it spins freely then the clutch needs to be replaced.

Other things would be inadequate bleeding of air in the coolant system, bad water pump or the thermostat is bad even though it's new.

But if this started from day one after engine work, then absolutely take it back. Way too much money to burn up an engine, unless it was free.

[BamaBus]

After reading your post in 2002 DT466e Decreasing Temp, I was wondering if the overheating caused the engine rebuild or did it occur after?

When was the CAC relocated, before the rebuild or after trying to correct overheating? As best I could tell from the video the trans cooler is in front of the radiator with the CAC directly behind both. Booyah45828 and cadillackid were having concerns about the stacking order and proper air flow.

[Compass]

Originally Posted by BamaBus

After reading your post in 2002 DT466e Decreasing Temp, I was wondering if the overheating caused the engine rebuild or did it occur after?

When was the CAC relocated, before the rebuild or after trying to correct overheating? As best I could tell from the video the trans cooler is in front of the radiator with the CAC directly behind both. Booyah45828 and cadillackid were having concerns about the stacking order and proper air flow.

The engine rebuild was previous th the overheating issue due to a blown head gasket.

The cooling system was rebuilt in the hopes of correcting the overheating issue. It was designed by my local diesel mechanic. There is about 2" of space between the components. Fan clutch is sound and checked at rebuild. A likely too small trans cooler was installed in front of the radiator with an auxiliary switch on the dash. Doesn't seem to help much when the AT545 is making heat 🙄

[sportyrick]

CAC behind radiator is a mistake, your adding heat to your compressed air instead of removing it. Climbing a hill means your engine is under higher load making more heat and compressor is compressing more air creating more heat and it's not getting removed which would make your engine run hot. Someone moved it to the rear to try and deal with the overheating by putting the radiator in first air but it's not the right move. Move it back to the front and add aux electric fans for hill climbing.